A process is disclosed for enhancing the production of light olefins with a catalytic reaction zone containing small pore zeolitic and non-zeolitic catalysts which can significantly improve the yield of ethylene and propylene in a process for the conversion of light olefins having four carbon atoms per molecule and heavier. Specifically, a C.sub.4 olefin stream from an ethylene production complex is converted in a reaction zone over a non-zeolitic catalyst at effective conditions to produce a product mixture containing ethylene and propylene. Ethylene and propylene are separated from the product mixture and recovered. A portion of the remaining heavy hydrocarbons and paraffins may be recycled to the reaction zone for further conversion, or oligomerized to produce valuable downstream products. The additional step of removing iso-olefins from the recycle stream provided significant advantages. The process of the present invention may be applied in commercial ethylene plants, in petroleum refining catalytic cracking operations, and in processes for the conversion of oxygenates such as methanol-to-olefins to enhance the production of ethylene and propylene.